The Earth ionosphere is a highly inhomogeneous medium containing electron density irregularities of various scales, from hundreds of kilometers to tens of centimeters. Understanding the mechanisms responsible for their formation is an important task for various practical applications such as communication, navigation, and safe satellite operation. Of special interest are the decameter irregularities that are abundant at E region heights of ~ 100 120 km. These are excited when enhanced electric field and plasma drifts are setup in the ionosphere. This thesis is aimed at studying the physics of decameter irregularity formation at E region heights with a focus on the extreme conditions of very strong electric fields (plasma flows) of > 50 mV/m (1000 m/s) for which the so called Farley-Buneman (FB) plasma instability is the dominating mechanism of irregularity excitation. The relationship between the irregularity velocity and plasma drift is investigated by considering data of the SuperDARN radar located at Stokkseyri, Iclenad. The radar detects echoes from the irregularities and is thus capable of measuring their velocity. The DMSP satellites measure the plasma drifts in situ at heights of ~ 800 km, but these measurements can be projected onto E region heights at high latitudes. By comparing the radar and satellite data in one direction, we show that irregularity velocity is smaller than the plasma drift by a factor of 2 3 with the stronger difference at faster flows. This contrasts with the theoretical expectation for the velocity to be close to 400 m/s, the nominal ion-acoustic speed at electrojet heights. A two-dimensional comparison is performed by considering a subset of the observations for which the HF echo velocity showed a cosine type variation with the radar look direction. This class of echoes is consistent with predictions of recent theories of the Farley-Buneman instability, but the irregularity velocity magnitude was found to be smaller than the ion-acoustic speed with occasional occurrence of velocities as small as 100 m/s. This implies that either recent theories of the Farley-Buneman instability should be modified or that the typical height of HF echoes is typically below 100 km. Various other properties of decameter irregularities are investigated and discussed in view of the existing theories.

In this thesis, several aspects of HF coherent backscatter from the high-latitude E and F regions are studied with the focus on the relationship between the echo characteristics and the parameters of the ionosphere. The Hankasalmi CUTLASS/SuperDARN radar is the primary instrument for the undertaken studies. <p> The starting point in the research is that coherent echo characteristics are affected by two factors: the plasma physics of magnetic field-aligned irregularity formation and the propagation conditions in that the HF radio waves need to be close to the normal of the Earths magnetic field to detect the irregularities. Since the mechanisms of irregularity production are believed to be different at various heights, observations in the E and F regions are considered separately. <p>For the F-region backscatter, we first investigate the ionospheric conditions necessary for backscatter to be detected at specific latitudes and in specific time sectors. To achieve this goal, two approaches are employed. First, a long-term statistical study of diurnal, seasonal and solar cycle effects on echo occurrence is done to assess the relative importance of changes in plasma instability conditions and radio wave propagation. Next, echo occurrence is studied for an area in which ionospheric parameters are measured by EISCAT and other instruments. Both approaches indicate that F-region echoes occur if the electric field is enhanced (above 5-10 mV/m). We show that, once the electric field is above the threshold, the echo power is only slightly dependent on it. We demonstrate that the strongest echoes are received when the F-region electron density is optimal for the selected range and altitude. This optimal value is found to be about 2x1011 m-3 for the Hankasalmi radar. The role of the conducting E region on irregularity excitation and HF radio wave absorption are discussed. <p>The next problem considered with respect to the F-region echoes is the relationship between the velocity of the F-region echoes and plasma convection. We give additional evidence that the observed HF line-of-sight velocity is the projection of the convection velocity on the radar beam and that the Map Potential technique (currently in use for building the global-scale convection maps) compares well with the local EISCAT convection measurements. <p> With respect to the E-region backscatter, two major features are studied. First, a more detailed (as compared to the standard SuperDARN approach) analysis of the spectra is performed. By employing the Burg spectrum analysis method, we show that the E-region echoes are double-peaked in ~35% of observations. Variations of the peak separation with the range and azimuth of observations are investigated. The occurrence of double-peak echoes is associated with scatter from two different heights within the E region. HF ray tracing indicates that for typical ionospheric conditions, scatter from the top and the bottom of the E region is possible at certain slant ranges. In the upper layer the plasma waves move with the velocity close to the ExB convection component. For the lower layer, the plasma wave velocity is reduced due to enhanced ion and electron collision frequencies. A second issue is how do the velocities of HF and VHF E-region echoes compare for observations along the same direction. We concluded that the velocity of E-region echoes at HF can be comparable to or below the VHF velocity and well below the ExB convection component, implying that the scatter can often come from the bottom of the electrojet layer. Other aspects of VHF velocities are also discussed.

In this thesis, several aspects of HF coherent backscatter from the high-latitude E and F regions are studied with the focus on the relationship between the echo characteristics and the parameters of the ionosphere. The Hankasalmi CUTLASS/SuperDARN radar is the primary instrument for the undertaken studies. <p> The starting point in the research is that coherent echo characteristics are affected by two factors: the plasma physics of magnetic field-aligned irregularity formation and the propagation conditions in that the HF radio waves need to be close to the normal of the Earths magnetic field to detect the irregularities. Since the mechanisms of irregularity production are believed to be different at various heights, observations in the E and F regions are considered separately. <p>For the F-region backscatter, we first investigate the ionospheric conditions necessary for backscatter to be detected at specific latitudes and in specific time sectors. To achieve this goal, two approaches are employed. First, a long-term statistical study of diurnal, seasonal and solar cycle effects on echo occurrence is done to assess the relative importance of changes in plasma instability conditions and radio wave propagation. Next, echo occurrence is studied for an area in which ionospheric parameters are measured by EISCAT and other instruments. Both approaches indicate that F-region echoes occur if the electric field is enhanced (above 5-10 mV/m). We show that, once the electric field is above the threshold, the echo power is only slightly dependent on it. We demonstrate that the strongest echoes are received when the F-region electron density is optimal for the selected range and altitude. This optimal value is found to be about 2x1011 m-3 for the Hankasalmi radar. The role of the conducting E region on irregularity excitation and HF radio wave absorption are discussed. <p>The next problem considered with respect to the F-region echoes is the relationship between the velocity of the F-region echoes and plasma convection. We give additional evidence that the observed HF line-of-sight velocity is the projection of the convection velocity on the radar beam and that the Map Potential technique (currently in use for building the global-scale convection maps) compares well with the local EISCAT convection measurements. <p> With respect to the E-region backscatter, two major features are studied. First, a more detailed (as compared to the standard SuperDARN approach) analysis of the spectra is performed. By employing the Burg spectrum analysis method, we show that the E-region echoes are double-peaked in ~35% of observations. Variations of the peak separation with the range and azimuth of observations are investigated. The occurrence of double-peak echoes is associated with scatter from two different heights within the E region. HF ray tracing indicates that for typical ionospheric conditions, scatter from the top and the bottom of the E region is possible at certain slant ranges. In the upper layer the plasma waves move with the velocity close to the ExB convection component. For the lower layer, the plasma wave velocity is reduced due to enhanced ion and electron collision frequencies. A second issue is how do the velocities of HF and VHF E-region echoes compare for observations along the same direction. We concluded that the velocity of E-region echoes at HF can be comparable to or below the VHF velocity and well below the ExB convection component, implying that the scatter can often come from the bottom of the electrojet layer. Other aspects of VHF velocities are also discussed.

The Earth ionosphere is a highly inhomogeneous medium containing electron density irregularities of various scales, from hundreds of kilometers to tens of centimeters. Understanding the mechanisms responsible for their formation is an important task for various practical applications such as communication, navigation, and safe satellite operation. Of special interest are the decameter irregularities that are abundant at E region heights of ~ 100 120 km. These are excited when enhanced electric field and plasma drifts are setup in the ionosphere. This thesis is aimed at studying the physics of decameter irregularity formation at E region heights with a focus on the extreme conditions of very strong electric fields (plasma flows) of > 50 mV/m (1000 m/s) for which the so called Farley-Buneman (FB) plasma instability is the dominating mechanism of irregularity excitation. The relationship between the irregularity velocity and plasma drift is investigated by considering data of the SuperDARN radar located at Stokkseyri, Iclenad. The radar detects echoes from the irregularities and is thus capable of measuring their velocity. The DMSP satellites measure the plasma drifts in situ at heights of ~ 800 km, but these measurements can be projected onto E region heights at high latitudes. By comparing the radar and satellite data in one direction, we show that irregularity velocity is smaller than the plasma drift by a factor of 2 3 with the stronger difference at faster flows. This contrasts with the theoretical expectation for the velocity to be close to 400 m/s, the nominal ion-acoustic speed at electrojet heights. A two-dimensional comparison is performed by considering a subset of the observations for which the HF echo velocity showed a cosine type variation with the radar look direction. This class of echoes is consistent with predictions of recent theories of the Farley-Buneman instability, but the irregularity velocity magnitude was found to be smaller than the ion-acoustic speed with occasional occurrence of velocities as small as 100 m/s. This implies that either recent theories of the Farley-Buneman instability should be modified or that the typical height of HF echoes is typically below 100 km. Various other properties of decameter irregularities are investigated and discussed in view of the existing theories.

“Adaptation – in the clutches of a discourse” is a project that investigates a discursive power and knowledge production. The project uses perspectives from philosophy, phenomenology, sociology, social constructivism and discourse theory in order to get a multilayered understanding of the uses of one manifested standardisation of normality or rather abnormality – the DSM manual. The DSM - Diagnostic and Statistical Manual for Mental Disorders – is an American manual used worldwide to understand mental disorders or irregularities. The inherent checklists that are used to diagnose individuals are based on the notions of normality within society. The DSM is constituted of checklists of different symptoms in behaviour, mood or other physiological effects that signifies mental disorders. How do the DSM and the uses of the DSM reflect the society? In the answer you will find economical, political and structural interests in using standardized ways of explaining the mental irregularities or differences of the human being.

Thesis (Ph. D.)--University of California, San Diego, 2002. / Vita. Includes bibliographical references (leaves 149-152).

Thesis (J.C.L.)--Catholic University of America, 1987. / Includes bibliographical references (leaves 172-179).

Cette thèse est un condensé de différentes irrégularités ou violations des droits dont sont victimes les travailleurs africains par leurs employeurs, en dépit des diverses législations en matière du travail qui existent dans tous les Etats parties. Au point où ils paraissent vivre une autre exploitation après l’esclavage et le colonialisme, cette fois-ci par leurs propres compatriotes. Ces maux sont constatés à la fois dans les rapports individuels de travail comme dans les rapports collectifs. C’est ainsi que certains salariés sont recrutés à la suite des tests de complaisance, sinon par la corruption, sans un document de travail ; d’autres travaillent pendant des années pour percevoir des salaires de misère, dans des conditions de travail affreuses. Quant aux irrégularités relatives aux rapports collectifs, pour mieux les duper, ces travailleurs sont exclus de la gestion de l’entreprise, ne bénéficiant ni du droit d’expression, ni du droit de participer aux performances de l’entreprise ; encore moins d’une représentation collective exemplaire par les délégués du personnel et les syndicalistes. En cas de litige, ils n’ont pratiquement pas une bonne protection étatique par les inspecteurs du travail et les magistrats. Ainsi pour sortir de cette crise aigüe dans le secteur du travail privé qui fait des ravages depuis plusieurs années après les indépendances, bien qu’il existe une réforme en vue à travers l’OHADA, les autorités nationales et internationales doivent veiller à la bonne application du droit du travail en prenant les mesures qui s’imposent. A défaut, la réforme du droit du travail envisagée par l’OHADA sera elle aussi vouée à l’échec. / This thesis is a compendium of various of rights which are currently victims of African workers by their employers despite various legislations in the work that exist in all states parties ; to the point where they appear to live another operation after slavery and colonialism. They live poverty on a daily basis. These evils are recognized both in the individual employment relationship as in public reports. This is how some employees are recruited following tests of complacency, if not corruptly there, without a working document ; others work for years to collect wages, without bonus, without leave, in terrible working conditions. As for collective reporting irregularities, to better trick these workers are excluded from the management company born with the right of expression or of the right to participate in the performance of the company still less than exemplary collective representation by the staff representatives and trade unionists. In case of dispute they have virtually no state protection by labor inspectors and judges. So out of this acute crisis in the sector private work that wreaks havoc for many years after independance, well there is a view through the OHADA reform, national and international authorities to ensure the correct application of the right to work by taking the measures that are necessary. Otherwise the reform of the labour law envisaged by the OHADA of the Right Business is also doomed to failure.

Complex magnetosphere-ionosphere coupling mechanisms result in high latitude irregularities that are difficult to characterize. Until recently, the polar and auroral irregularities remained largely unexplored. Inadequate infrastructures to deploy and maintain advanced dual frequency Global Navigation Satellite System (GNSS) receivers at high latitudes, especially in the Southern hemisphere, makes such an investigation a formidable task. Additionally, the complicated geometry of the magnetic field lines in these regions pose challenges in designing global scintillation models. This dissertation takes some steps towards bridging these gaps while advancing the state-of-the-art high latitude irregularity studies. In the first part of this dissertation, we briefly describe the Autonomous Adaptive Low-Power Instrument Platforms (AAL-PIP) experimental setup. These space science instrument platforms are being deployed in remote locations in Antarctica, improving the coverage of GNSS data availability. We explain in detail the method developed for analyzing high rate (typically 50 Hz) data from a novel dual-frequency Global Positioning System (GPS) receiver called Connected Autonomous Space Environment Sensor (CASES). We also report first observations from CASES at high latitudes. From this study, we established that CASES can be reliably used as a science grade GPS scintillation monitor. Following this, a novel three dimensional (3D) electromagnetic (EM) wave propagation model called "Satellite-beacon Ionospheric-scintillation Global Model of the upper Atmosphere" (SIGMA) was developed to simulate GNSS scintillations on ground. GPS scintillation simulations of significantly high fidelity are now possible with this model. While the model is global, it is the first such model which accounts for the complicated geometry of magnetic field lines at high latitudes. Using SIGMA, a sensitivity study is presented to understand the effect of geographical, propagation and irregularity parameters on the phase scintillations. This allows us to reduce the dimensionality of the design space while solving the inverse problem described next. In the final part, we utilize the tools developed for GPS measurement analysis and SIGMA to characterize the high latitude irregularities. We propose an inverse modeling technique to derive irregularity parameters by comparing the high rate (50 Hz) GNSS observations to the modeled outputs. We consider interhemispheric high latitude datasets for this investigation. We also implement SIGMA for analyzing a substorm event observed by AAL-PIP stations. One of the unique contributions of this research is to demonstrate that such an inverse modeling technique can form a basis in the investigation of the ionospheric irregularities. Moreover, availability of ample auxiliary data from multi-instrument observations can assist in this quest of understanding the physics of high latitude irregularities and their generation mechanisms. / Ph. D.

The research explores aspects of road surface measurement and monitoring, targeting some of the main challenges in the field, including cost and portability of high-speed inertial profilers. These challenges are due to the complexities of modern profilers to integrate various sensors while using advanced algorithms and processes to analyse measured sensor data. Novel techniques were proposed to improve the accuracy of road surface longitudinal profiles using inertial profilers. The thesis presents a Half-Wavelength Peak Matching (HWPM) model, designed for inertial profilers that integrate a laser displacement sensor and an accelerometer to evaluate surface irregularities. The model provides an alternative approach to drift correction in accelerometers, which is a major challenge when evaluating displacement from acceleration. The theory relies on using data from the laser displacement sensor to estimate a correction offset for the derived displacement. The study also proposes an alternative technique to evaluating vibration velocity, which improves on computational factors when compared to commonly used methods. The aim is to explore a different dimension to road roughness evaluation, by investigating the effect of surface irregularities on vehicle vibration. The measured samples show that the drift in the displacement calculated from the accelerometer increased as the vehicle speed at which the road measurement was taken increased. As such, the significance of the HWPM model is more apparent at higher vehicle speeds, where the results obtained show noticeable improvements to current techniques. All results and analysis carried out to validate the model are based on real-time data obtained from an inertial profiler that was designed and developed for the research. The profiler, which is designed for portability, scalability and accuracy, provides a Power Over Ethernet (POE) enabled solution to cope with the demand for high data transmission rates.